1. Field of the Invention
The invention in general relates to a method of and an apparatus for controlling the energization of an electrical load in circumstances where the supply of current is limited and electrical energy reserves have to stay within certain limits, and more particularly to such a method and apparatus for controlling the energizing of an electrical load the current consumption of which exceeds the current generating capability of the electrical system to which it is connected without discharging a storage battery below a predetermined level.
2. Description of the Prior Art
Automotive vehicles are equipped with a current generator or alternator for generating current and with a storage battery. While the current produced by the generating equipment is in normal circumstances sufficient to satisfy all the requirements of the electrical system of the vehicle, it is, nevertheless, limited. For at times the current required by the system may exceed the current generated. In such circumstances the difference may be supplied, at least for a limited time, from the battery.
For instance, the temporary energization of a heatable windshield may add a load to the electrical system which may consume current exceed the generating capability of the generator. The excess would have to be drawn from the battery in a manner well known. However, unless carefully monitored, this could lead to lowering the battery charge to a level too low to restart the engine after it has been cut.
3. Objects of the Invention
Therefore, it is an object of the invention to provide a method of and apparatus for preventing an excessive discharge of a battery.
Another object of the invention resides in the provision of a method and apparatus for preventing excessive discharge of a battery where current required to feed electrical loads is in excess of current generated.
A further object of the invention resides in providing a method and an apparatus for use in an automotive vehicle for preventing excessive current drain from a battery where temporarily activated electrical loads require current in addition to the total capacity the generating equipment is capable of providing.
Yet another object of the invention is to provide a method and an apparatus for monitoring excessive current consumption and temporarily reducing such consumption in response to the charge level of a battery being lowered to a predetermined level.
Still another object of the invention resides in the provision of a method and apparatus for disconnecting an electrical load from an electrical system of an automotive vehicle in response to signals indicating a predetermined level of charge of the battery.
A more general object of the invention resides in the provision of a method and apparatus for establishing values representative of upper and lower charge levels of a battery.
It is also an object of the invention to provide a method of an apparatus for simulating predetermined maximum and minimum charge levels of an electrical storage battery in an automotive vehicle and in response to the minimum charge level to disconnect predetermined current consuming equipment.
Other objects of the invention w ill in part be obvious and will in part appear hereinafter. The invention accordingly comprises a method and apparatus possessing the construction, combination of elements and arrangement of parts which are exemplified in the following detailed disclosure.